Abnormalities of tooth numbers are common congenital malformations that can occur either as isolated findings or as part of a syndrome. These abnormalities have significant clinical implications on the quality of life of the affected individual. Indeed they may result in psychological and social problems, functional limitations, lengthy treatments by multidisciplinary teams of professionals, and high treatment costs usually not reimbursable by dental insurance. While dentists may treat patients for the symptoms, they are not well prepared, for example, to discriminate sporadic isolated hypodontia from familial isolated hypodontia and syndromic hypodontia. This is most relevant for the purposes of more accurate and timely diagnosis, patient treatment and counseling, and the potential to initiate novel research related to abnormalities of tooth numbers. Without a clear understanding of the different factors involved in the production of abnormalities of tooth numbers, diagnosis and treatment can be delayed, health services may be withheld and insurers remain unwilling to consider coverage for various treatments. The proposed Conference will highlight new basic research advances, chair-side clinical observations and population-based studies in driving new translational connections related to tooth numbers. While the overarching goal is to improve the quality of life of individuals with special health care needs, the conference aims are to transfer and disseminate new oral health knowledge gained from research to the special care dentists, to enhance their diagnostic and treatment capabilities and to encourage them to participate in a Practice Based Research Network. The 2016 joint meeting of the Special Care Dentistry Association and the International Association for Disabilities and Oral Health attracts oral health care professionals who serve patients with special needs. This venue presents an excellent opportunity to transfer new knowledge from the research laboratory to clinicians working with patients daily. The Conference significance is two fold: (i) it will promote the timely transfer of research knowledge and its implications for oral health and (ii) it will improve the communication and understanding of the causes of dental abnormalities which is crucial to achieve an adequate diagnosis and provide treatment alternatives or even cures for common, but on many occasions, devastating oral dental abnormalities.